Armature rebound damper mechanism



April 24, 1962 H. E. MORRIS ARMATURE REBOUND DAMPER MECHANISM Filed Nov. 23, 1960 FlG.l

f/erberz 6 Morris INVENTOR.

BYMfiM ATTORNEY United States Patent 3,031,549 ARMATURE REBOUND DAMPER MECHANISM Herbert E. Morris, Roanoke, Va., assignor to General Electric Company, a corporation of New York Filed Nov. 23, 1960, Ser. No. 71,300 4 Claims. (Cl. 200 -87) My invention relates to switching apparatus and particularly to fluid immersed switching apparatus. It has to do with means to prevent reestablishment of the are at the switch contacts due to rebounce of the armature upon its movement to the open position against a stop.

My invention has for its object to provide simple and economical means to absorb the kinetic energy of the movable switch components upon movement thereof to the open position of the switch andagainst a stop thereby to prevent rebounce of the switch members and possible reignition of the are between the contacts of the switch.

A further object of my invention is to utilize the fluid in which the switch apparatus may be immersed to cushion the impact of the movable switch member against its limiting stop thereby to prevent objectionable rebounce of the switch members.

In accord with my invention the stop, which limits the movement of the movable element when the switch is opened, is mounted for movement in response to the impact of the movable switch element. It is provided with the baflle immersed in the fluid, which baffle moves with the stop, upon impact thereby, but has sufliciently broad surface area presented to the fluid to resist said movement and to absorb the kinetic energy of the movable switch element thereby to dampen or cushion the impact of the switch element against the stop. After the impact the switch element and stop may be resiliently restored to normal position by means of a spring.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims. My invention, itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing which in FIG. 1 illustrates a switch mechanism incorporating my invention. FIG. 2 shows the switch actuating mechanism when the switch is in the closed position, and FIG. 3 is a similar view when the switch actuated mechanism is in its extreme open position in impact with its limiting stop.

Referring to FIG. 1, I have shown a switch apparatus comprising movable contacts 1, 2 and 3 thereof, which are operated by an armature member 4 on which is mounted a core member 5 which cooperates with a further stationary core member 6 which serves as an electromagnet to attract the core member 5 and actuate the armature to close the switch. I have shown a coil 7 about the electromagnet 6 which may be energized to close the switch.

FIG. 1 illustrates the switch members 1, 2, 3 and armature 4 all in the position which they assume when the switch is in its open position. In that position the armature 4 rests against a stop 9 carried by a support 10. This stop 9 forms one end of a shaft 12 which projects through an aperture in the end of the support and which carries at its other end a baffile 14 illustrated in the form of a disk.

Preferably all the parts of the switch are immersed in oil, or suitable insulating fluid, as indicated by the dashed lines about the switch with the result that any movement of armature 4 against the stop 9 causes movement of the baffie 14 against the oil. This movement of the 'bafile against the oil absorbs the kinetic energy of the impacting armature 4 and cushions such impact and dampens the movement of the armature thereby preventing any rebounce of the armature.

winding 7 may be sulficiently rapid that upon impact of the armature 4 with the stop 9 the armaturemay rebounce carrying the contacts 1, 2 and 3 back toward, and possibly into, engagement with their cooperating fixed contacts, or sufficiently close thereto, to reignite the are that was broken upon the outward movement of the contacts.

The movement of the stop 9 and baffle 14 against the resistance offered by the fluid cushions this impact and prevents any such rebounce. Thereafter the stop and bafile may be restored to their normal position by means of a suitably arranged spring, such as that shown at 16 about the shaft 12.

FIG. 2 shows the armature 4 with the magnetic core member 5 in engagement with the core 6 of the electromagnet as when the switch is in its closed position. It better illustrates the support 10, stop 9, battle 14 and spring member 16 in the position which they occupy when the switch is closed. It will be noted that the spring has one end engaging the support 10 and the other end engaging the stop 9, thereby holding the bafie 14 substantially in engagement with the support 10.

FIG. 3 shows the parts in the position which they occupy in response to impact between armature 4 and stop 9. The stop 9 is driven to the left forcing the bafile 14 against the resistance of the fluid thereby producing the desired cushion elfect, and comprising the spring 16 so that, after absorption of the kinetic energy of the movable parts of the switch, the spring may restore the stop 9 and the baffle 14 to the position shown in FIG. 2.

It will be noted that the stop, or damping mechanism 9, 14, 16 is not attached to the armature 4 and, therefore, does not retard movement of the armature in its normal actuation to the open position of the switch. Moreover, this stop mechanism does not operate until substantially the end of the movement of the armature. It thus has no effect on the speed of pick up or drop out of the switch. Malfunction in this mechanism does not prevent operation of the switch.

Optimum results for any particular application may be had by altering the characteristics of the damper mechanism. That is, the size, shape and configuration of the baffle, the material of the mechanism and the speed, direction and amount of travel of the damper all affect the action of the damping mechanism by changing the amount ofenergy transferred to the fluid and, of course, may be taken into account in the design of the damping mechanism for optimum performance in any particular application.

While I have shown a particular embodiment of my invention, it will, of course, be understood that various modifications may bemade both in the structure and instrumentalities employed without departing from the true spirit and scope of my invention, as set forth in the appending claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a switch actuator immersed in an incompressible liquid and having an armature movable from a closed position of the switch to an open position of said switch and further having a stop to limit such movement upon opening the switch, the combination of means supporting said stop for movement in response to impact by said armature, and a baffle carried by said stop and immersed in the switch immersing liquid and presenting sufiicient area thereto to retard movement of the stop upon impact by said armature thereby to prevent rebounce by said armature.

2. In a switch actuator immersed in an incompressible liquid and having an armature movable from a closed position of the switch to an open position of said switch and further having a stop to limit such movement upon opening the switch, the combination of means supporting said stop for movement in response to impact. by said armature, a bafiie carried by said stop and immersed in the switch immersing liquid and presenting sufficient area thereto to retard movementof the stop upon impact by said armature thereby to prevent rebounce by said armature, and resilient means to restore said stop and bafile to normal positions in said fluid after movement there- ".f-rom by reason oft impact by said armature.

3. In combination, a switch actuator immersed in an incompressible liquid and having an armature movable from a closed position of the switch to an open position of said switch, a stop to limit such movement of said armature upon opening saidswitch, a support mounting said sto'p ior movement relative to said support upon impact by said armature, a baifieattached to said stop for movement therewith against said switch 'immersingliquid 20 in response to impact of said armature against said stop, 1 said bafile presentingarea to said liquid suflicient to cushion said impact and reduce rebounce of said armature.

4. .In combination, a switch actuator immersed in an incompressible liquid and having an armature movable from a closed position of the switch to an open position of said switch, a stop to limit suchtmovement of said armature upon opening said switch, a fixed support for said stop, said support having an aperture therein, and

said stop having a shaft extending through said aperture and carrying at its opposite enda baffle immersed in said switch immersing liquid, and a spring member between 1 said stop and bafile, whereby upon impact-ofsaid armature against said stop, said stop and shaft force said' baffie against said liquid deforming said spring and cushioning said impact to preventre'bounce of saidarmature, said spring having sufficient restoring force to return-said :baiile shaft and stop to the normal positionthereof. 

